I've had my target mandarin for about 3 months...(hardly long enough to call it a success..) Fat and happy even with 8 leopard wrasses sharing her home! Lots of pods in the fuge though. She may eat frozen because she gets very excited when I feed, but I don't stop to be certain. Will do tomorrow.
I had a red mandarin I bought off of Craigslist a few months years ago... It lived in my 54 corner for another year until my heater died, it was one of the first to go. It ate mysis, brine, anything it could fit in its mouth!